1. Field of the Invention
The present invention relates to a retainer for a nose pad on a frame of a pair of eyeglasses, the pair of eyeglasses being composed of two frames, each holding a lens, and a member, such as a bridge, connecting the frames together. A respective nose pad is secured to each frame. Each such retainer consists of a flat, one-piece nose pad support, or pad arm, and of a plastic retaining element for the nose pad. The retaining element can be inserted into a receiving opening of the nose pad support and locked therein by engagement of the nose pad support with a constriction of the retaining element.
2. Prior Art
Retainers of this type are known in many structural designs, all of which have in common that, on the one hand, the nose pad support, or pad arm, which can be fixed on one of the eyeglasses frames, and, on the other hand, the nose pad can be brought into engagement with each other by means of essentially correspondingly shaped parts or partial sections, so that a more or less permanent connection of these components, which is essential for the wearing properties of the eyeglasses, is achieved.
Examples of such retaining mechanisms are disclosed in German Letters Patents DE-PS 27 32 860 and DE-PS 27 12 897 and German Published, Non-Examined Patent Application DE-OS 28 35 116.
French Patent Publication FR-A 2 492 545 which relates to this type of structure, also discloses such a system.
Connecting the nose pads to the pad arm is considerably difficult since, because of the small dimensions of the components concerned which are in the millimeter range, the definition of the forces and stresses on the material when the retaining element is snapped in or pulled out of the pad arm and their translation into concrete dimensional structures can quickly lead to unsatisfactory results, if it is not possible to achieve an optimum structural adaptation. This may be the reason why the systems disclosed in the above mentioned patent publications have not been successful in the marketplace in spite of their basic functional abilities.
The requirement for as simple as possible and therefore cost-effective manufacture and processing of the components does not take second place to the requirement for perfect and satisfactory functioning of these components, even in case of constant stresses, which should also aid the comfortable wear of the eyeglasses. For example, the solutions of German Letters Patent DE-PS 28 35 116 are unacceptable because there the pad arm consists of two separate parts which as a rule must be soldered together. Therefore, a separate process step is required here, which even with the most careful work necessarily will produce unsatisfactory soldered connections. This, in turn, leads to a considerable amount of waste because of the breaking of the soldered connection between the pad arm and the separately manufactured retainer box. Although such waste is only on the order of 0.5 to 1% of the total production, the end result is that in case of complaints about defective connections (broken-off pads) of eyeglasses, as a rule the entire pair of eyeglasses becomes unusable because with most eyeglass models the repair costs are more on the order of the value of the entire eyeglasses than on the order of the value of the pad arm with the box soldered on. Therefore the mentioned waste leads to an over-proportional value loss in spite of the numerically small proportion in the sense that the resulting damage is far above the value of the defective components as such. Again and again this results in complaints and difficulties with customers.
This situation is improved by the solution disclosed in French Patent Publication FR- A-2 492 545 in that there a profiled wire or the like is used as the pad arm or at least as a part of the pad arm, which results in a simplification.
However, this reference and all other above mentioned references have in common that the objective of such a connection between the pad arm on the one hand and the nose pad on the other consists in achieving simple assembly as well as simple disassembly of these two parts. Thus, it is to be made possible for the optometrist to pull a possibly damaged or aged nose pad out of the pad arm without the use of tools and to replace it with a new component.
This objective may be the reason why the known solutions have attempted to achieve the resilience required for this in that either the retaining section of the nose pads or the receiving section of the pad arm (or both, as in FR-A-2 492 545) have slits for achieving suitable pressing together or widening during assembly and disassembly.
With the dimensions in the millimeter range mentioned above, together with the unavoidable manufacturing tolerances, however, these slits lead to an inadequate definition of the engagement and disengagement properties of the nose pad, since obviously they further increase the tolerances present as such because of the manufacture of the components. The result of these inadequacies is then reflected in unsatisfactory functioning, either in that the desired assembly and disassembly behavior in actual use is stiffer than planned, or that the connection is too loose, so that even though the connection of the two components is satisfactory, the danger of unintentional loss of a nose pad increases over-proportionally.